Closure for hand-holes of boilers



(No Model.)

J. D. SMITH. CLOSURE FOR HAND HOLES 0F BOILERS. No. 546,789. Patented Sept. 24, 1895.

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flz'rzvfss Es jjjj) firm-1mm? NITE STATES FFIQE ATENT JOHN D. SMITH, OF DALTON, ASSIGNOR OF TWO-THIRDS TO IV. LlBlBEY EATON, OF HOLYOKE, MASSACHUSETTS.

HOLESOF BOILERS.

SPECIFICATION forming part of Letters Patent No. 546,789, dated September 24, 1895.

Application filed March 20. 1895.

To all whom it may concern.-

Be it known that I, JOHN D. SMITH, a citizen of the United States of America, residing at Dalton, in the county Berkshire and State of Massachusetts, have invented new and useful Improvements in Closures for Hand-Holes of Boilers, of which the following is a specification.

This invention relates to improvements in hand-hole or manhole covers for boilers and the fastening means therefor, the principal object being to overcome the difficulty commonly experienced by reason of the nut which screws onto the retainingbolt for the handhole cover being so burned onto the bolt as to render its detachment oftentime impossible, or, at best, very inconvenient.

The object of this invention is attained by the means substantially as hereinafter described, and set forth in the claims, whereby the place of screw engagement of the nut with the bolt which holds the hand-hole cover is immersed in orprotccted by the water within the boiler against the burning action.

The invention is shown in the accompanying drawings, in Which Figure 1 is a sectional view through the portion of the boiler comprising the handhole and the hand-hole cover and confining means therefor. Fig. 2 is an inner face view of Fig. 1. Fig. 3 is a perspective view of one of the nuts.

In the drawings, A represents a portion of the boiler, having, as usual, the hand-hole A 13 represents the hand-hole cover.

0 is the yoke, and D is the retaining-bolt.

In this construction the cover B is centrally drilled and tapped and is countersunk or has the round socket a at and surrounding the inner orifice of the screw-tapped hole. The bolt D is, before the cover is placed in the boiler, screwed through and beyond the cover, its screw-threaded portion 1) receiving at the inner extremity the nut G, which is shown as of the form externally seen in Figs. 1 and 3that is, its inner half or portion is turned round and of smaller diameter than the aforesaid socket a, while the outer portion thereof is hexagonal or of equivalent form to be engaged by a Wrench. The depth of the round part of the nut is slightly greater than the Serial No. 542,496. (No model.)

manently at its inner end to the cover, both bolt and cover had to be thrown away.

In many boiler-furnaces the bolt D and nut H are subjected to such intense heat that upon desiring to remove the hand-hole cover the said nut is found to be burned onto the outer end of the bolt, so that it cannot be turned off, and it has been necessary to either twist off the end of the bolt or split the nut with a cold-chisel, leaving the bolt ruined. Now, under the present invention, where the nut H is burned onto the bolt by the application of a wrench, the bolt may be turned out from the cover and nut at the inner side thereof, which latter is found to be in a good state of preservation by reason of its immersion within the water. in the boiler. The belt is then thrown away and a new bolt and nut H are supplied at a very small cost, and yet assuring much economy over the methods heretofore pursued, Where the bolt D was a permanent part of the cover, which necessitated supplying a new cover as well as bolt.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, is-

1. The combination with the boiler having the hand or manhole, of the hand-hole cover having the screw-threaded hole through it with the enlarged orifice at the inner side, the boltscrew-th'reading through the cover and protruding inwardly beyond it, and a nut adapted to seat itself and be packed in the base of the said orifice as it is screwed upon the inner extremity of the bolt, and the yoke, O, and nut, H, externally applied, substantially as described.

2. The combination with the boiler having the hand-hole, of the hand-hole cover internally applied and closing said hole and havthooireular orifice or socket at thoinner side, of the bolt, and the yoke C, and nut, II, ex

the bolt screw-threading through the cover ternally applied about and upon the bolt,suband protruding; inwardly beyond it, the nut stantiully as described.

havingthe hexagonalor equivalent formation JOHN D. SMITH. and also having its forward portion round \Vitnesses:

and adapted to enter Within said socket as \VM. S. BELLO\VS,

the nut is screwed upon the inner extremity \V. L. EATON. 

